<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/jquery-1.11.3.js"></script>
    <script>
        $(document).ready(function () {
            //这里开始写代码
            var a = 10;

        });
        $(document).ready(function(){
            //这里开始写代码
            alert(a)
        });


    </script>
</head>
<body>
<input type="button" value="点我">


</body>
</html>